Advanced endovascular graft and delivery system

ABSTRACT

Embodiments are directed in part to endovascular prostheses and methods of deploying same. Embodiments may be directed more specifically to stent grafts and methods of positioning and deploying such devices within the body of a patient.

RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/297,219, filed Nov. 15, 2011, by J. Vinluan et al., titled “AdvancedEndovascular Graft and Delivery System”, which claims priority under 35U.S.C. section 119(e) from U.S. Provisional Patent Application Ser. No.61/414,375, filed Nov. 16, 2010, by J. Vinluan et al., titled “AdvancedEndovascular Graft and Delivery System”, each of which are incorporatedby reference herein in their entirety.

FIELD OF THE INVENTION

Some embodiments relate in part to endovascular prostheses and methodsof deploying same. Embodiments may be directed more specifically tostent grafts and methods of making and deploying same within the body ofa patient.

BACKGROUND

An aneurysm is a medical condition indicated generally by an expansionand weakening of the wall of an artery of a patient. Aneurysms candevelop at various sites within a patient's body. Thoracic aorticaneurysms (TAAs) or abdominal aortic aneurysms (AAAs) are manifested byan expansion and weakening of the aorta which may be a serious and lifethreatening condition for which intervention is generally indicated.Existing methods of treating aneurysms include invasive surgicalprocedures with graft replacement of the affected vessel or body lumenor reinforcement of the vessel with a graft.

Surgical procedures to treat aortic aneurysms can have relatively highmorbidity and mortality rates due to the risk factors inherent tosurgical repair of this disease as well as long hospital stays andpainful recoveries. This is especially true for surgical repair of TAAs,which is generally regarded as involving higher risk and more difficultywhen compared to surgical repair of AAAs. An example of a surgicalprocedure involving repair of an AAA is described in a book titledSurgical Treatment of Aortic Aneurysms by Denton A. Cooley, M.D.,published in 1986 by W. B. Saunders Company.

Due to the inherent risks and complexities of surgical repair of aorticaneurysms, endovascular repair has become a widely-used alternativetherapy, most notably in treating AAAs. Early work in this field isexemplified by Lawrence, Jr. et al. in “Percutaneous Endovascular Graft:Experimental Evaluation”, Radiology (May 1987) and by Mirich et al. in“Percutaneously Placed Endovascular Grafts for Aortic Aneurysms:Feasibility Study,” Radiology (March 1989).

When deploying devices by catheter or other suitable instrument, it maybe advantageous to have a flexible and low profile stent graft anddelivery system for passage through the various guiding catheters aswell as the patient's sometimes tortuous anatomy. Many of the existingendovascular devices and methods for treatment of aneurysms, whilerepresenting significant advancement over previous devices and methods,use systems having relatively large transverse profiles, often up to 24French. Also, such existing systems have greater than desired lateralstiffness, which can complicate the delivery process.

In addition, the sizing of stent grafts may be important to achieve afavorable clinical result. In order to properly size a stent graft, thetreating facility typically must maintain a large and expensiveinventory of stent grafts in order to accommodate the varied sizes ofpatient vessels due to varied patient sizes and vessel morphologies.Alternatively, intervention may be delayed while awaiting custom sizestent grafts to be manufactured and sent to the treating facility. Assuch, minimally invasive endovascular treatment of aneurysms is notavailable for many patients that would benefit from such a procedure andcan be more difficult to carry out for those patients for whom theprocedure is indicated.

In addition to low profile, other features may be desirable as well. Forexample, it is well known that the AAA and TAA patient populationpresents a wide variety of anatomy for treatment. One particularchallenge is providing stent-graft treatment to patients with eithertortuous anatomies and/or small landing zones for stent-graft that havebarbed stents to engage the luminal surface of the aorta or othervascular.

What have been needed are stent graft systems and methods that areadaptable to a wide range of patient anatomies and that can be safelyand reliably deployed using a flexible low profile system.

SUMMARY

Some embodiments include advanced stent graft systems comprising, eithersingularly or in combination, a number of features. In some embodiments,a stent graft may include a short or no proximal stent portions. Inother embodiments, proximal stent portions may include one or aplurality of barb structures. Other embodiments include variousradiopaque marker embodiments.

Some embodiments may include advanced delivery systems having acentering device, such as a basket or an inflatable structure. Otherembodiments show various constraints for loading of stent grafts withincatheters. Other embodiments show various constraints in combinationwith centering devices.

Some embodiments of a stent graft may include a graft body including aflexible tubular main body having an inner lumen configured to confine aflow of fluid therethrough and a graft collar disposed at a proximal endof the main body. The stent graft may also include a stent having adistal stent portion which is disposed distally of a proximal edge ofthe graft collar. The distal stent portion may be at least partiallysecured to the graft collar. The stent may also have a proximal stentportion which is disposed proximally of the graft collar, includes atleast one barb extending radially outward therefrom and includes anaxial length of about 1 mm to about 5 mm.

Some embodiments of a method of deploying a stent graft in a patient'svessel include providing a stent graft having a graft body including aflexible tubular main body with an inner lumen configured to confine aflow of fluid therethrough and a graft collar disposed at a proximal endof the main body. The stent graft may also include a stent having adistal stent portion which is disposed distally of a proximal edge ofthe graft collar and which is at least partially secured to the graftcollar. The stent may also have a proximal stent portion which isdisposed proximally of the graft collar, includes at least one barbextending radially outward therefrom and includes an axial length ofabout 1 mm to about 5 mm. Thereafter, the stent graft may be axiallypositioned at a desired site within the patient's vessel with the atleast one barb disposed axially coextensive with a viable landing zoneof the patient's vessel. The stent may then be deployed so as to engagethe tissue of the viable landing zone of an inner luminal wall of thepatient's vessel.

Some embodiments of a delivery system for delivering a stent graftinclude a delivery catheter having an elongate shaft with a proximalsection and a distal section. The system may also include a stent grafthaving a main graft body with an inner lumen configured for confining aflow of blood therethrough. The stent graft may be loaded on theproximal section of the delivery catheter with the elongate shaftdisposed within the inner lumen. In addition, the delivery system mayalso include an expandable centering device disposed on the elongateshaft within the inner lumen of the stent graft. The centering devicemay be configured to expand from a radially contracted state to aradially expanded state for centering the elongate shaft and stent graftof the delivery system toward a midline or longitudinal axis of apatient's vessel when introduced into the patient's vessel. In somecases, the centering device includes an expanding basket, the baskethaving elongate tines that extend substantially parallel to the elongateshaft of the delivery catheter in the radially contracted configuration.The elongate tines may also be configured to bow radially outwardly fromthe elongate shaft in a substantially concentric arrangement in theradially expanded configuration. The centering device may also includean inflatable structure having a collapsed deflated state and anenlarged inflated state. In some cases, in the enlarged inflated state,the centering device may have a substantially cylindrical configurationincluding vias that extend from ports in a proximal surface of thecentering device to respective ports in a distal surface of thecentering device. The vias may be configured to provide for continuousflow of blood through the inflatable centering device and deliverysystem during inflation of the centering device and deployment of thestent graft.

Some embodiments of a method of centering a delivery system duringdeployment of a stent graft include providing a delivery system fordelivering a stent graft. Such a delivery system may include a deliverycatheter having an elongate shaft with a proximal section and a distalsection. The delivery system may also include a stent graft having amain graft body with an inner lumen configured for confining a flow ofblood therethrough and a stent secured to the main graft body, the stentgraft being loaded on the proximal section of the delivery catheter withthe elongate shaft disposed within the inner lumen. The delivery systemmay further include an expandable centering device disposed on theelongate shaft within the inner lumen. The centering device may beconfigured to expand from a radially contracted state to a radiallyexpanded state for centering the elongate shaft and stent graft of thedelivery system toward a midline longitudinal axis of a patient's vesselwhen introduced into the patient's vessel. Thereafter, the deliverycatheter may be positioned within a patient's vessel such that the stentgraft is axially positioned at a desired site within the patient'svessel. The expandable centering device may be in the radiallycontracted state during the positioning process in some cases. Theexpandable centering device may then be expanded to the radiallyexpanded state to center the elongate shaft and stent graft of thedelivery system toward the longitudinal axis of the patient's vessel. Inaddition, the stent of the stent graft may then be deployed so as toengage an inner luminal wall of the patient's vessel.

Some embodiments of a delivery system for delivering a stent graftinclude a delivery catheter having an elongate shaft with a proximalsection and a distal section. The delivery catheter may also include areleasable stent constraint system disposed on the proximal sectionelongate shaft. In some cases, the stent constraint system may include acrown constraint sleeve having a rigid tubular structure disposed aboutthe elongate shaft with a plurality of crown restraint extensionsextending distally from the crown constraint sleeve. The crown restraintextensions may generally be circumferentially spaced from each other.The catheter may also have a strut support assembly which is slidinglydisposed about the elongate shaft distally adjacent the crown constraintsleeve. The strut support assembly includes a plurality of strutsupports which are circumferentially aligned with respective crownrestraint extensions of the crown constraint sleeve and which extendradially away from a longitudinal axis of the elongate shaft. Theconstraint system has a docked state wherein the strut supports formclosed but openable crown constraint passages between the strut supportsand respective crown constraint extensions of the crown constraintsleeve. The constraint system also includes an open state wherein thestrut support assembly is spaced axially away from the crown constraintsleeve and the crown restraint passages are opened to allow radialexpansion of stent crowns disposed therein. The delivery system may alsoinclude a stent graft including a self-expanding stent secured to aproximal end of a main graft body. In some cases, the main graft bodymay have an inner lumen configured for confining a flow of bloodtherethrough. The stent graft is loaded on the proximal section of thedelivery catheter with the elongate shaft disposed within the innerlumen and a plurality of proximal stent crowns disposed within closedcrown restraint passages of the stent constraint system. So configured,the strut support assembly is in a docket state.

Some embodiments of a method of deploying a stent graft includeproviding a delivery system for delivering a stent graft. The deliverysystem may include a delivery catheter having an elongate shaft with aproximal section and a distal section and a releasable stent constraintsystem disposed on the proximal section elongate shaft. In some cases,the stent constraint system may include a crown constraint sleeveincluding a rigid tubular structure disposed about the elongate shaftwith a plurality of crown restraint extensions extending distally fromthe crown constraint sleeve. Generally, the crown restraint extensionsmay be circumferentially spaced from each other. The stent constraintsystem may also include a strut support assembly which is disposed aboutthe elongate shaft distally adjacent the crown constraint sleeve. Thestrut support assembly may include a plurality of strut supports whichare circumferentially aligned with respective crown restraint extensionsof the crown constraint sleeve and which extend radially away from alongitudinal axis of the elongate shaft. The constraint system isconfigured to have a docked state wherein the strut supports form closedbut openable crown constraint passages between the strut supports andrespective crown constraint extensions of the crown constraint sleeve.There is also an open state of the constraint system wherein the strutsupport assembly is spaced axially away from the crown constraint sleeveand the crown restraint passages are opened to allow radial expansion ofstent crowns disposed therein. The delivery system further includes astent graft having a self-expanding stent secured to a proximal end of amain graft body. The main graft body may have an inner lumen configuredfor confining a flow of blood therethrough. In some instances, the stentgraft may be loaded on the proximal section of the elongate shaft withthe elongate shaft disposed within the inner lumen and a plurality ofproximal stent crowns disposed within closed crown restraint passages ofthe stent constraint system with the strut support assembly in a docketstate. Such a stent graft may be axially positioning at a desired sitewithin the patient's vessel. Thereafter, the crown restraint sleeve maybe axially separated from the strut support assembly so as to open thecrown restraint passages allowing crowns of the stent contained withinthe crown restraint passages to radially expand. In some instances, thecrown constraint sleeve may be secured to elongate shaft and the strutsupport assembly may be slidingly disposed about elongate shaft distallyadjacent the crown constraint sleeve. In such a case, axially separatingthe crown restraint sleeve from the strut support assembly so as to openthe crown restraint passages allowing crowns of the stent containedwithin the crown restraint passages to radially expand may includedisplacing the strut support assembly in an axial direction relative tothe crown constraint sleeve and the elongate shaft. In some cases, thestrut support assembly is secured to the elongate shaft and the crownconstraint sleeve is slidingly disposed about elongate shaft proximallyadjacent the crown constraint sleeve. In such an embodiment, axiallyseparating the crown restraint sleeve from the strut support assembly soas to open the crown restraint passages allowing crowns of the stentcontained within the crown restraint passages may include displacing thecrown constraint sleeve in a proximal direction relative to the strutsupport assembly and the elongate shaft.

Some embodiments of a delivery system for delivering a stent graftinclude a delivery catheter having an elongate shaft with a proximalsection and a distal section. The delivery catheter may also include areleasable stent constraint system disposed on the proximal sectionelongate shaft. The stent constraint system may include a stentconstraint sleeve which has a rigid tubular structure slidably disposedabout the elongate shaft between a distal position and a proximalposition. The stent constraint sleeve may also include a plurality ofcrown sections that extend distally from the crown constraint sleeve andare circumferentially spaced from each other. The constraint system mayfurther include a plurality of strut supports which are secured to theelongate shaft distally adjacent the stent constraint sleeve, which arecircumferentially spaced from each other and which extend radially awayfrom a longitudinal axis of the elongate shaft. Such a constraint systemmay have a constraint state wherein the stent constraint sleeve isdisposed in the distal position and a deployment state wherein the stentconstraint sleeve is in the proximal position. The delivery catheter mayalso include an expandable basket having a plurality of elongate tineswhich are disposed in a substantially tubular configuration, whichextend axially along the elongate shaft of the delivery catheter in aposition distally adjacent the stent constraint sleeve, and which areconfigured to bow radially outward upon reduction of a separationbetween proximal ends of the elongate tines and distal ends of theelongate tines. In addition, the delivery system may have a stent graftincluding a flexible main graft body and a self-expanding stent. Themain graft body portion may include an inner lumen configured forconfining a flow of blood therethrough, a proximal end and a distal end.The self-expanding stent may have a proximal end, a distal end securedto the proximal end of the main graft body, and a plurality of proximalstent crowns which include at least one barb. For such a configuration,the stent graft may be loaded on the proximal section of the elongateshaft with the elongate shaft disposed within the inner lumen. Theplurality of proximal stent crowns which include at least one barb maybe disposed within and radially constrained by the stent constraintsleeve with the stent constraint sleeve in the distal position. Inaddition, at least one elongate tine of the expandable basket may bedisposed beneath a stent crown that includes a barb, the at least oneelongate tine being configured to apply outward radial force on thestent crown upon deployment of the stent and expansion of the expandablebasket.

Some embodiments of a method of deploying a stent graft includeproviding a delivery system for delivering a stent graft. In some cases,such a delivery system may include a delivery catheter having anelongate shaft with a proximal section and a distal section. Thedelivery catheter may also include a releasable stent constraint systemdisposed on the proximal section elongate shaft. The stent constraintsystem may include a stent constraint sleeve which has a rigid tubularstructure slidably disposed about the elongate shaft between a distalposition and a proximal position. The stent constraint sleeve may alsoinclude a plurality of crown sections that extend distally from thecrown constraint sleeve and are circumferentially spaced from eachother. The constraint system may further include a plurality of strutsupports which are secured to the elongate shaft distally adjacent thestent constraint sleeve, which are circumferentially spaced from eachother and which extend radially away from a longitudinal axis of theelongate shaft. Such a constraint system may have a constraint statewherein the stent constraint sleeve is disposed in the distal positionand a deployment state wherein the stent constraint sleeve is in theproximal position. The delivery catheter may also include an expandablebasket having a plurality of elongate tines which are disposed in asubstantially tubular configuration, which extend axially along theelongate shaft of the delivery catheter in a position distally adjacentthe stent constraint sleeve, and which are configured to bow radiallyoutward upon reduction of a separation between proximal ends of theelongate tines and distal ends of the elongate tines. In addition, thedelivery system may have a stent graft including a flexible main graftbody and a self-expanding stent. The main graft body portion may includean inner lumen configured for confining a flow of blood therethrough, aproximal end and a distal end. The self-expanding stent may have aproximal end, a distal end secured to the proximal end of the main graftbody, and a plurality of proximal stent crowns which include at leastone barb. For such a configuration, the stent graft may be loaded on theproximal section of the elongate shaft with the elongate shaft disposedwithin the inner lumen. The plurality of proximal stent crowns whichinclude at least one barb may be disposed within and radiallyconstrained by the stent constraint sleeve with the stent constraintsleeve in the distal position. In addition, at least one elongate tineof the expandable basket may be disposed beneath a stent crown thatincludes a barb, the at least one elongate tine being configured toapply outward radial force on the stent crown upon deployment of thestent and expansion of the expandable basket. For such a system thestent graft may be axially positioned at a desired site within thepatient's vessel and the stent constraint sleeve axially displaced in aproximal direction from the distal position to the proximal position torelease the crowns of the stent to radially expand. In addition, theexpandable basket may be radially expanded such that at least oneelongate tine of the expandable basket which is disposed beneath acorresponding crown having a barb extends radially outward and appliesan outward radial force to the corresponding crown so as to facilitateengagement of the barb with tissue of the patient's vessel at thedesired site.

Certain embodiments are described further in the following description,examples, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an embodiment of an inflatable stentgraft.

FIG. 2 shows the stent graft of FIG. 1 as placed in a vessel lumen of apatient having a TAA condition in partial section.

FIG. 3 shows an enlarged view in partial section of a barb of a proximalstent of the stent graft of FIG. 1 penetrating and engaged with tissueof the patient's vessel.

FIG. 4 shows an embodiment of a stent portion of a stent graft.

FIG. 5 shows an enlarged view of a connection between a proximal stentportion and distal stent portion.

FIG. 6 shows an embodiment of a stent portion of a stent graft.

FIG. 7 shows an embodiment of a stent portion of a stent graft.

FIG. 8 shows an embodiment of a barb structure of a stent.

FIG. 9 shows an embodiment of a barb structure of a stent.

FIG. 10 shows an embodiment of a barb structure of a stent.

FIG. 11 shows an embodiment of a barb structure of a stent.

FIG. 12 shows an embodiment of stent structure formed onto a graftcollar.

FIG. 12A is a transverse cross section view of the graft of FIG. 12taken along lines 12A-12A of FIG. 12.

FIG. 13 shows an embodiment of stent structure formed onto a graftcollar.

FIG. 14 shows an embodiment of stent structure formed onto a graftcollar.

FIG. 15 shows an embodiment of a barb structure as positioned withrespect to a graft collar or proximal edge thereof and an embodiment ofa radiopaque marker.

FIG. 16 shows an embodiment of a barb structure as positioned withrespect to a graft collar or proximal edge thereof and an embodiment ofa radiopaque marker.

FIG. 17 shows an embodiment of a barb structure as positioned withrespect to a graft collar or proximal edge thereof and an embodiment ofa radiopaque marker.

FIG. 18 shows an embodiment of a barb structure as positioned withrespect to a graft collar or proximal edge thereof and an embodiment ofa radiopaque marker.

FIG. 19 shows an exemplary catheter delivery system embodiment.

FIG. 20 shows an enlarged view of the nosecone of the delivery catheterof FIG. 5.

FIG. 21 shows an enlarged view of a handle portion of the deliverycatheter of FIG. 5.

FIG. 22 shows an embodiment of a delivery system including an expandablebasket arrangement in a radially constrained state.

FIG. 23 shows the expandable basket arrangement of FIG. 22 in a radiallyexpanded state with closer spacing between distal and proximal ends ofthe basket than in FIG. 22.

FIG. 24 depicts a delivery catheter being positioned inside a patient'saorta.

FIG. 25 shows a transverse cross section view of the delivery catheterwithin the patient's aorta of FIG. 24 taken along lines 25-25 of FIG.24.

FIG. 26 shows the delivery catheter of FIG. 24 with a centering basketdeployed.

FIG. 27 shows the delivery catheter of FIG. 24 with the centering basketdeployed within an inner lumen of a graft body section of a stent graftwith proximal and distal stents partially deployed.

FIG. 28 is a perspective view of an embodiment of a centering deviceincluding an inflatable structure.

FIG. 29 is a transverse cross section view of a dual lumen elongatetubular member that includes a lumen for a guidewire and an inflationlumen for the inflatable structure.

FIG. 30 is an end view of the inflatable structure of FIG. 28.

FIG. 31 shows a perspective view of a portion of an embodiment of adelivery catheter that includes a sleeve coupled to a multi-lumen shaftby a push rod.

FIG. 32 is an elevation view of a section of a delivery catheter thanincludes an expandable member having a basket configuration with thebasket in a shortened and radially expanded state.

FIG. 33 shows an embodiment of a basket configuration of a deliverycatheter with the basket and a stent of the stent graft loaded thereonin a radially constrained state.

FIG. 34 shows the delivery catheter and stent graft of FIG. 33 with thestent partially deployed and the basket in a radially expanded state.

FIG. 35 is a perspective view of a portion of an embodiment of a stentconstraint system with the stent of a stent graft not shown for purposesof illustration.

FIG. 36 is a perspective view of the stent constraint system of FIG. 35with the stent shown in a radially constrained state loaded onto thedelivery catheter and held in place by the constraint system.

FIG. 37 is an elevation view of the constraint system of FIG. 36 withthe stent deployed from the constraint system.

FIG. 38 is a perspective view of a portion of an embodiment of a stentconstraint system with a stent in a partially deployed state and a graftbody of the stent graft not shown for purposes of illustration.

FIG. 39 is a perspective view of the stent constraint system of FIG. 38with the stent fully deployed.

FIG. 40 is a perspective view of a portion of an embodiment of a stentconstraint system with a sleeve thereof in a proximal position.

FIG. 41 is a perspective view of the constraint system of FIG. 40 withthe sleeve displaced distally relative to the position of a support andcrown constraint assembly shown in FIG. 40.

FIG. 42 is an elevation view of the constraint system of FIG. 40 crownconstraint assembly and support disposed in a proximal positionconfigured to constrain a stent which is not shown for purposes ofclarity of illustration.

FIG. 43 is an elevation view of the constraint system as shown in FIG.42 but with the crown constraint assembly disposed distally of theproximal edge of the sleeve but still engaged with the support.

FIG. 44 shows the constraint system of FIG. 43 with the crown constraintassembly disposed distally of the sleeve and distally disengaged fromthe support so as to fully release a previously constrained stent.

FIG. 45 shows a perspective view of an embodiment of a stent constraintsystem including an expandable basket and stent in a radiallyconstrained configuration.

FIG. 46 is a perspective view of the constraint system of FIG. 45 with asleeve displaced proximally relative to the stent and basket so as topartially release the stent and allow the expandable basket to radiallyexpand.

FIG. 47 is a perspective view of the constraint system of FIG. 46wherein the stent graft previously constrained by the constraint systemhas been deployed and the tines of the expandable basket are applying anoutward radial force against respective struts and barbs of the stent inorder to more fully engage target tissue of a patient's vessel.

FIG. 48 is an enlarged elevation view in partial section of a tinedisposed adjacent a strut and barb of a stent and applying an outwardradial force against the barb towards tissue of the patient's vesselwall.

The drawings illustrate embodiments of the invention and are notlimiting. For clarity and ease of illustration, the drawings are notmade to scale and, in some instances, various aspects may be shownexaggerated or enlarged to facilitate an understanding of particularembodiments.

DETAILED DESCRIPTION

Embodiments may be directed generally to methods and devices fortreatment of fluid flow vessels with the body of a patient. Treatment ofblood vessels is specifically indicated for some embodiments, and, morespecifically, treatment of aneurysms, such as thoracic aortic aneurysmsand abdominal aortic aneurysms. Prosthetic devices used for thetreatment of fluid flow vessels within a patient's body are typicallysubjected to a variety of forces such as pulsatile expansion andcontraction of a patient's vessels as well as significant hemodynamicforces resulting from a high rate of flow of blood through the vessels.Often diseased vessels that require treatment are tortuous and narrowmaking percutaneous delivery of the prosthetic to the treatment sitedifficult. As such, it may be important for a prosthetic such as a stentgraft to be configured to securely anchor to an inner luminal surface ofthe patient's vessel to prevent axial slippage or movement of the deviceafter deployment. Such anchoring may be necessarily carried out in ashort axial section of relatively healthy vessel tissue in order toproperly secure the device. As such, some stent graft embodiments mayrequire a configuration that may be securely anchored within suchconstraints. It may also be important for the stent graft to establish agood seal between an outside surface of the stent graft and the innerluminal surface of the patient's vessel in order to effectively isolatethe vascular defect such as an aneurysm from the hemodynamic forces ofblood flow. Proper placement of the prosthetic at deployment may also bea challenge and thus some delivery system embodiments used to deploy aprosthetic for treatment of a patient's aneurysm may be configured toaccurately position the stent graft as well as allow for partialdeployment and repositioning of the stent graft prior to fulldeployment.

FIG. 1 is a perspective view of an inflatable stent graft 100 madeparticularly for TAA. Such a stent graft 100 may have features which aresimilar to or the same as those of the Ovation™ Stent Graft System ofTriVascular Inc. Stent graft 100 may include a proximal stent 102 havinga substantially tubular overall configuration, a main graft body 104also having a substantially tubular overall configuration, inflationchannels 106 disposed on the flexible main graft body 104 and distalstent 108 having a substantially tubular configuration. Stents 102 and108 may be made from any suitable material. For example, self-expandingstent embodiments 102 and 108 may be made from superelastic materialssuch as NiTi alloy or the like or any other suitable high strengthmaterial. Stent embodiments 102 and 108 that are configured to beballoon expandable may be made from other high strength materials suchas stainless steel, MP35N, Elgiloy® or the like. Inflation sealing rings110 a and 110 b may be included to provide a better sealing between anoutside surface of the stent graft 100 and an inner luminal surface ofthe patient's vessel. Such an improved seal may be helpful in reducingor preventing the possibility of endoleaks that might occur around thefabric or layers of the main graft body 104 stent graft. The inflationsealing rings or expandable cuffs 110 a and 110 b may have an interiorvolume that is in fluid communication with an interior volume of theinflation channels 106.

The distal end of the proximal stent 102 is secured to a connection ringor sealing ring disposed within a proximal end of the main graft body104. A proximal end of the distal stent 108 is secured to a connectionring or sealing ring disposed in a distal end of the main graft body104. The stents 102 and 108 may be secured by any suitable method ordevice discussed or incorporated herein such as the “dogbone” typeconnection discussed below with regard to FIG. 5.

Main graft body 104 may be made from any suitable flexible biocompatiblematerial for constructing such stent grafts. For example, body 104 mightbe made from a fabric such as Dacron®, from a polymer such as afluoropolymer like polytetrafluorethylene (PFTE) or expanded PTFE(ePTFE) or any other suitable material. Ins some instances, it may bedesirable for the material of the main graft body to be configured to bethin and flexible in order to pack tightly for a reduced profile duringdelivery and be configured to confine a flow of blood through a tubularstructure made of the material. In cases, the type of material used forthe main graft body and whether the main graft body includes inflationchannels and inflation sealing rings may be of less importance. Someembodiments may, however, include a main graft body made of PTFE andhave inflation channels and sealing rings. In some cases the main graftbody 104 may have an axial length of about 50 mm to about 400 mm, morespecifically, about 100 mm to about 300 mm. In some cases, an innerlumen 107 configured to confine a flow of blood or other bodily fluidtherethrough of the main graft body 104 my have a transverse diameter ordimension of about 15 mm to about 39 mm, more specifically, about 30 mmto about 36 mm. The proximal and distal stents 102 and 108 may havedimensions commensurate with those of the main graft body 104. Thestents 102 and 108 may have any suitable number of crowns or apicesdepending on the transverse expanded dimension or diameter and axiallength of the stents 102 and 104. In some cases, the sinusoidalstructure of the stents 102 and 104 may have about 3 to about 16 apicesper side.

Embodiments having such construction which may be substituted into orincluded with any of the suitable embodiments discussed here aregenerally disclosed in commonly-owned U.S. Pat. No. 6,331,191, filedNov. 25, 1998, by Chobotov, titled “Layered Endovascular Graft”; U.S.Pat. No. 6,395,019 filed Aug. 14, 1998, by Chobotov, titled“Endovascular Graft”; U.S. Pat. No. 6,602,280 filed Jan. 31, 2001, byChobotov, titled “Delivery System and Method for ExpandableIntracorporeal Device”; U.S. Pat. No. 6,733,521 filed Apr. 11, 2001, byChobotov, et al., titled “Delivery System and Method for EndovascularGraft”; U.S. Pat. No. 6,761,733 filed Jul. 27, 2001, by Chobotov et al.,titled “Delivery System and Method for Bifurcated Endovascular Graft”;U.S. Pat. No. 6,776,604 filed Dec. 20, 2001, by Chobotov et al., titled“Method and Apparatus for Shape Forming Endovascular Graft Material”;U.S. Pat. No. 7,066,951 filed Apr. 17, 2003, by Chobotov, titled“Delivery System and Method for Expandable Intracorporeal Device”; U.S.Pat. No. 7,081,129 filed Apr. 24, 2002, by Chobotov, titled“Endovascular Graft”; U.S. Pat. No. 7,147,660 filed Dec. 20, 2002, byChobotov et al., titled “Advanced Endovascular Graft”; U.S. Pat. No.7,147,661 filed Dec. 20, 2001, by Chobotov et al., titled “RadiallyExpandable Stent” and U.S. Pat. No. 7,150,758 filed Mar. 6, 2003, byKari et al., titled “Kink Resistant Endovascular Graft”; and in UnitedStates Published Patent Application Numbers 2005/0027347, Aug. 13, 2003,by Chobotov et al., titled “Endovascular Graft Joint and Method forManufacture”; 2006/0222596 filed Apr. 1, 2005, by Askari et al., titled“Non-Degradable, Low Swelling, Water Soluble Radiopaque HydrogelPolymer”; 2006/0233990 filed Apr. 13, 2005, by Humphrey et al., titled“PTFE Layers and Methods of Manufacturing”; 2006/0233991 filed Apr. 13,2005, by Humphrey et al., titled “PTFE Layers and Methods ofManufacturing”; 2009/0082845 filed Sep. 26, 2007, by Chobotov, titled“Alignment Stent Apparatus and Method”; 2009/0082846 filed Sep. 26,2007, by Chobotov, titled “Asymmetric Stent Apparatus and Method” and2009/0099649 filed Oct. 3, 2008, by Chotobov et al., titled “ModularVascular Graft for Low Profile Percutaneous Delivery”—all such patentsand patent applications are fully incorporated by reference in theirentirety herein. In addition, any suitable stent graft, delivery systemor components thereof disclosed in these incorporated patent and patentapplications may be substituted for embodiments of same discussedherein.

FIG. 2 shows an elevation view in partial section of the stent graftembodiment 100 of FIG. 1 as implanted and deployed in an aorta 101 of apatient having a TAA condition 202. As shown, stent graft 100 isimplanted in such a manner so as to establish a good hemostatic sealbetween an outside surface of the stent graft 100 at the inflation seals110 a and the proximal stent deployed at a suitable landing zone so asnot to occlude the left subclavian artery 204 with the fabric or otherflexible layers of the stent graft 100. In this case, the aneurysm 202has been effectively isolated from the nominal blood flow through thevessel 101. The nominal blood may flow pass through the inner lumen ofthe main graft body 104 and stents 102 and 108 after such deployment ofthe stent graft 100. In some cases, proximal stent 102 may be deployedproximally of the left subclavian artery 204 of the patient and optionalbarbs shown in FIG. 3 may be used to better fixate the stent grafts 102and 108 by engaging with the luminal surface of the aorta 101. Stentgraft 100 as well as others discussed herein may also be deployed suchthat the left subclavian artery 204 is covered by the fabric or layersof the main graft portion 104—up to the left common carotid artery witha trans-graft between the left subclavian and one of the adjoiningarteries.

As mentioned above, patient anatomy may be widely varied—with somepatients having extreme neck angulation and curvature of the aorta (asdepicted in vessel element or section 206 and vessel element or section208 of FIG. 2. Vessel section 206 may be described as being thelesser-curve side of the aorta and vessel section 208 may be describedas the greater-curve section of the patient's aorta 101. Vessel sectionof the greater curve 208 may also have a short axial length section or“landing zone” for securing a proximal stent 102 of a stent graft 100.In some cases, such extreme conditions of short landing zones may ruleout a particular patient for treatment by any known endograft becausethe risk of certain failure modes may be too great. Such failure modesmight include stent breakage (because of extreme hemodynamic conditionsin the thoracic aorta); insufficient sealing or the like. It will beappreciated that such extreme conditions of neck angulation andcurvature and short landing zones may also appear in AAA conditions and,therefore, the devices and techniques of the present disclosure may alsobe desirable in the treatment of AAA conditions—or anywhere in apatient's body where such conditions may exist.

FIG. 3 is an elevation view in partial section of a proximal portion ofa proximal stent 220 of a stent graft such as stent graft 100 discussedabove. An optional barb 228 of the stent 220 is extending from a strutof the stent 220 at an angle pointing substantially in a distaldirection along a direction of a flow of blood in the vessel 101 of thedeployment. The barb 228 is also angled slightly radially outwardtowards the vessel wall 101 in order to penetrate and mechanicallyengage the tissue of the patient's vessel 101. Such a barb arrangementmay be incorporated in to any suitable stent embodiment discussedherein. In addition, although FIG. 3 depicts the engagement of aproximal stent with a patient's vessel 101, a similar arrangement anddeployment configuration may be used for distal stents, such as distalstent 108 and the like but with the directions of the stent and barb 228reversed relative to the direction of blood flow as indicated by arrow120.

Several embodiments of stents that might serve as either proximal stentsor distal (if any) stents on a stent graft are discussed herein. If astent graft is destined to be placed into an area of challenginganatomy, short landing zones or in an area where the hemodynamics arechallenging (e.g. high pressure and blood velocity, such as found nearthe heart in the thoracic aorta), then it may be desirable to have astent that is not susceptible to failure (e.g. stent fractures) or todamaging the patient's vasculature (in the case of movement of the stentin vivo due to blood flow).

FIG. 4 shows an embodiment of a stent 220 of a stent graft 221 whichincludes a proximal portion 222 of the stent 220 and a distal portion224 of the stent 220. Distal portion 224 in this case may bemechanically mated to a graft collar 236 of a graft body portion 225 ofthe stent graft 221 in any known manner or fashion—such as overlaying alayer of graft material and mating (as shown herein via sintering or thelike), or by sewing the distal portion 224 onto the fabric material ofthe body portion of the stent graft. The material of the graft bodyportion 225 may be the same as discussed above with regard to stentgraft 100. The graft body portion 225 may have a generally tubularconfiguration that extends along a longitudinal axis 223 of the stentgraft 221. The stent graft 221 may also share other suitable materials,dimensions and features of stent graft 100 such as inflatable channels106 and inflation sealing rings or cuffs 110 etc.

Proximal portion 222 of the stent 220 may be mated to the distal portion224 via connection 226 (e.g. a dogbone structure) or may be madeintegrally with the distal portion. Optional barbs 228 may beconstructed on the proximal portion 222 of the stent 220—the barbs 228may be either welded or otherwise mechanically mated to the proximalportion 222. In other embodiments, barbs 228 may be made integrally withthe proximal portion 222 of the stent 220 and may also be located on astrut 229 of the proximal portion 222 (as shown), or may be made at theapices of the proximal portion 222. The stents disclosed hereingenerally may be constructed out of any material suitable for thisapplication—e.g. stainless steel, self-expanding metal such assuperelastic alloys (NiTi or the like), etc.

Distal portion 224 of stent 220 may have a first axial length andproximal portion 222 of stent 220 may have a second axial length. Asshown, the axial length of the proximal portion 222 is longer than theaxial length of the distal portion 224. This may be advantageous in somecases where a patient has a challenging landing zone in the vessel101—but in other cases, it may not be desirable from the standpoint ofthe stent's dynamic behavior in vivo. For example, in the case of a TAA,a stent graft 221 having a long proximal portion 222 might be subject tomovement or hemodynamic forces that may cause injury to the patient'saorta due to movement of the proximal portion 222 against the patient'svasculature 101. In some embodiments, an axial length of proximalportion 222 may be about 20 mm to about 30 mm and an axial length of thedistal portion 224 may be about 10 mm to about 15 mm. The proximalportion 222 may be secured to the distal portion 224 of the stent graft221 by any suitable device or method. In some cases the attachment 226may be an integral attachment, in some cases there may be a linked ormechanical attachment such as the dogbone type attachment shown in moredetail in FIG. 5.

FIG. 6 shows another embodiment of a stent 230 of a stent graft 231 thatmay have desirable characteristics for providing good clinicalperformance in difficult anatomical conditions such as the anatomicalconditions noted above including a highly angulated vessel configurationor difficult landing zone. For example, stent 230, which may be aself-expanding stent embodiment with a generally sinusoidal zig-zagconfiguration, may be configured to have an overall axial length that isless than an overall axial length of the stent 220 shown in FIG. 4. Inaddition, it may be possible to use either a short proximal portion orextension 234 extending proximally out from the graft collar 236 anddistal portion 232—or no proximal portion 234 at all. In such cases, thebarbs 235 of the stent might be substantially located at the top ofgraft collar 236. As shown in FIG. 6, it may be desirable for the numberof proximal portions 234 to be some fractional proportion to the numberof apices 233 of distal portion 232 (e.g. one half). In otherembodiments, stent proximal portion or extension 234 may includedifferent fractional proportions. In some embodiments, the shortproximal portion or extension 234 may have an axial length on order ofabout 1 mm to about 14 mm, more specifically, about 1 mm to about 5 mm.The distal portion 232 may have an axial length on the order of about 10mm to about 15 mm in some cases. In the case where the proximal portion232 is about 1 mm or less in axial length, it may be considered that theproximal portion 234 may be just a barb 235 that sits atop the apices233 of the distal portion 232 and may be just even with a top orproximal end of the graft collar 236.

In some embodiments of the stent graft 231, the stent graft 231 mayinclude a graft body 225 including a flexible tubular main body havingan inner lumen configured to confine a flow of fluid therethrough asshown in FIG. 6. The graft collar 236 may be disposed at a proximal endof the main body. The stent graft 231 may also include the stent 230having a distal stent portion 232 which is disposed distally of aproximal edge of the graft collar 236. The distal stent portion 232 maybe at least partially secured to the graft collar 236. In some cases,the entire distal stent portion 232 may be secured to the graft body ata position such as the graft collar 236. The distal stent portion 232may be secured by any suitable means, including disposing the distalportion 232 between adjacent layers of material of the graft collar 236or of the graft body 225 generally. The stent 230 may also include theproximal stent portion 234 which is disposed proximally of the graftcollar 236 and may include at least one barb 235. The barb 235 may beextending generally in a distal direction and also extend somewhatradially outward from the proximal stent portion 234 and may have anaxial length of about 1 mm to about 5 mm. In some instances, theproximal stent portion 234 includes a plurality of barbs 235 disposedproximally of the proximal edge of the graft collar 236. Self-expandingembodiments of the stent 230 and barbs 235 may include superelasticmaterials such as superelastic alloys including NiTi alloys and thelike. In some cases, the stent graft 231 may have a stent 230 with aproximal portion 234 wherein no barbs are disposed more than about 5 mmfrom the proximal edge of the graft collar 236.

In some cases, the distal stent portion 232 may include a continuoussinusoidal configuration and the at least one barb 235 is disposed on astrut or extension of the proximal stent portion 234 that extendsproximally from an apex of the sinusoidal configuration of the distalstent portion 232 as shown in FIG. 6. In other cases, the distal stentportion 232 may include a distal portion of a continuous sinusoidalconfiguration and the at least one barb may be disposed on a strut of aproximal portion 234 of the sinusoidal configuration that extendsproximally from the proximal edge of the graft collar 236 and forms theproximal stent portion of the stent as shown in FIG. 14. In someinstances, the stent 230 may include a balloon expandable stent that ismade of a high strength biocompatible material that is subject toelastic deformation during radial expansion from a radially constrainedstate suitable for percutaneous delivery to an expanded deployed statesuitable for engaging an inner luminal wall of a patient's vessel. Suchhigh strength materials for balloon expandable stent construction mayinclude high strength alloys such as stainless steel. Such stentembodiments, such as stent 230 or any other suitable stent embodimentdiscussed herein may include at least one eyelet on a distal portion ofthe stent and the distal portion of such a stent may be secured to agraft collar 236 or any other suitable portion of a graft body portionof a stent graft with a flap of flexible material that may be disposedthrough the eyelet and secured to the graft collar. Such a flap ofmaterial (as shown in FIGS. 7 and 14) may be secured to the graft collaror graft body by adhesive bonding, welding, sintering or the like.

Some embodiments of a method of deploying such a stent graft in apatient's vessel 101 may include providing the stent graft 231 above.Thereafter, the stent graft 231 may be axially positioned at a desiredsite within the patient's vessel 101 (as shown in FIG. 27 and discussedbelow) with the at least one barb 235 disposed axially coextensive witha viable landing zone of the patient's vessel 101. The stent 230 maythen be deployed so as to radially expand and physically engage thetissue of the viable landing zone of an inner luminal wall of thepatient's vessel 101. In some cases, deploying the stent 230 may includedeploying the stent disposed at a proximal end of the stent graft 231disposed towards a source of blood flow in the patient's vessel 101,such as the patient's heart (not shown). In some instances wherein thestent 230 includes a self-expanding stent, deploying the stent 230includes releasing a radial constraint from the stent 230 in a radiallyconstrained state. In some embodiments wherein the stent 230 includes aballoon expandable stent, deploying the stent 230 includes expanding thestent 230 radially outward with an expandable member (not shown)disposed within an inner lumen of the stent 230. In some such cases, theexpandable member may include an inflatable balloon and deploying thestent may include expanding the stent radially outward by inflating theinflatable balloon with a source of pressurized fluid.

In some embodiments, it may be desirable to have a stent of a stentgraft (such as stent graft 100, stent graft 221, stent graft 231 or anyother suitable stent graft discussed herein) that includes barbs (suchas barbs 228, 235 or the like) that are disproportionately positionedand/or populated on one side of the stent. For example, in a highlyangulated aorta 101, the top side of a stent graft may tend to take thebrunt of the hemodynamic forces and pressures (being on the greatercurve 208 of the aorta as shown in FIG. 2) than the side of the stentgraft that lies along the lesser curve 206 of the aorta 101. In such acase, it may be desirable to configure a stent such that the top sideportion of the stent includes more barbs (e.g. along every apices) and alesser number or density of barbs along the low portion of the stent(e.g. to have barbs at every other apices).

In some cases, distal portion 232 of the stent 230 may be mated to thegraft mechanically by encapsulating the metallic stent in between two ormore layers of graft material and the graft layers mated or otherwisebonded together—e.g. between two layers of PTFE and sintered into place.The distal portion 232 could also be mated by sewing the distal portionto the graft materials of the graft body 225 or in any other knownmanner of mating or bonding layers.

FIG. 7 shows an embodiment of a stent graft 241 that may have similarfeatures, dimensions and material with respect to stent graft 231, wherea distal portion 232 of a stent 240 is mated to the graft collar 236 byusing flaps of material 241 (e.g. PTFE) that are placed through eyelet242. Fluorinated ethylene propylene (FEP) may be incorporated aroundeyelet 242 to improve the mating of the stent 240 to the graft collar236. One advantage of using flaps of materials may be to improve thetensile strength of the retention of the stent 240 to the graft. The useof flaps may also reduce the amount of graft collar needed to anchor thestent 240. In some embodiments, the proximal portion 234 may have alength on order of about 5-15 mm and the distal portion 232 may have alength on order of about 5-15 mm.

FIGS. 8-11 show various embodiments of barbs that may be used for anysuitable stent graft embodiment discussed in the present application.Barbs 260 may be placed at the apices of proximal portions (such asproximal portion 234 or distal portions 232, if there is no proximalportion 234) of stents or at the end of a strut or extension 262. Thebarb embodiments 260 and struts or extensions 262 may be disposed ateither the proximal end or distal end of any suitable stent graft uponwhich they are used. Barbs 260 may be biased outward towards the tissueof an inner luminal surface of a patient's vessel 101 as shown in FIG. 3to better engage the luminal surface of the patient's vessel 101, suchas the aorta. In some embodiments, the barbs 260 may have a lengthextending from the strut of about 1 mm to about 5 mm.

FIG. 8 shows a barb 260 that extends along a center line or longitudinalaxis of strut 262 which has support legs extending to each side of thebarb to a proximal most section or apex 264 from which the barb 260extends. FIG. 9 illustrates a barb 260 that has a substantially hookshaped configuration wherein the barb is formed from an extension of thestrut 262 which bends around in a u-turn and has a sharpened tip. Insome cases, the strut 262 may be bent around in a u-turn at an angle ofabout 150 degrees to about 190 degrees. FIG. 10 illustrates adouble-barb configuration wherein a strut 262 hooks around on two sidesdisposed opposite each other to form two barbs 260. Each barb 260 isformed by a u-shaped type pattern or configuration similar to the barbconfiguration shown in FIG. 9 but on two opposed sides of the strut. Thebarbs may extend distally along the strut 262 over a length of about 1mm to about 5 mm, in some embodiments. FIG. 11 shows a double barbconfiguration similar to that of FIG. 10 with a first barb 260 on oneside of the strut and a second barb 260 on an opposite side of the strut262. However, in the embodiment of FIG. 11, a first barb 260 extendsfrom a proximal apex of the strut and a second barb 260 extends from aposition distal to the apex of the strut 262. In the embodiment shown,the second barb 260 extends from a position on the strut 262 that issubstantially axially coextensive with the sharpened tissue penetratingpoint or tip of the first barb 260.

FIGS. 12 and 13 show embodiments of incorporation of the stent structure230 within the graft material and configurations for securing the stentstructure to the graft body. Dashed line 302 shown in FIGS. 12 and 13represents a proximal boundary of a portion of the main graft where theinner lumen 107 defined by the main body of the stent graft issubstantially cylindrical. Proximal of line or axial positionrepresented by line 302 the inner lumen may begin to flare in a proximaldirection to a larger inner luminal transverse dimension. In particular,graft collar 236 which is proximal of line 302, may be constructed toflare outwardly from line 302 in a proximal direction. This flaredconfiguration may be advantageous to help create a proper sealing of theaneurysm from the blood flow. This may be particularly the case whenthere is sufficient radial force provides by the stent to hold graftcollar 236 against the luminal surface. FIG. 12 shown a stent graftembodiment having a configuration wherein a proximal sealing ring 304(for example, sealing ring 304 could be an inflatable portion filledwith a gel capable of hardening to provide a seal against blood flow) isdistal of line 302. FIG. 13 depicts a similar sealing ring 304 that isconfigured to be proximal of, or straddling, line 302. It may bedesirable in some cases to include a sealing ring 304 which is disposedproximal of line 302 because it may tend to allow for a shortening ofthe edge of graft collar 236. This may be useful for the treatment ofpatient having a shortened landing zone or area for securing mechanicalattachment or fixation members of a stent, such as barbs or the like.

FIG. 14 depicts a somewhat flattened rendition of an embodiment of astent portion 311. Although only a portion 311 of the stent is shown inthe flattened illustration, the stent portion may be representative of acomplete stent 300 having a typical configuration of the stentsdiscussed herein generally with a substantially tubular or cylindricalshape with a stent element of high strength material extending about alongitudinal axis of the stent in a somewhat sinusoidal undulatingpattern. For the embodiment shown in FIG. 14, anchoring of the stent 300to a graft body section may be provided at least in part by flapmaterial 306 threaded through eyelet 242 in a manner similar to thatshown in the embodiment of FIG. 7. The flap material 306 may be selectedto have a high tensile strength and bonding compatibility with thematerial of the graft body. In some cases, the flap 306 may include thesame material as that of the main graft body. In some instances, suchmaterial may include Dacron®, PTFE or any other suitable material. Flapmaterial 306 may be secured to the main graft body of the stent byadhesive bonding, such as with the use of FEP or the like, welding,sintering or any other suitable method. The flaps 306 may have asomewhat ribbon like configuration with a width that is substantiallygreater than the thickness of the flaps 306 in order to spread thetensile load imposed on the eyelet 242 over a greater area of the graftcollar 236 or graft body generally. Barb 308 of stent 300, as shown, maybe integrally constructed with the strut 311 such that there is no jointbetween the strut 313 and the barb 308 and the material of the strutextends continuously into the barb 308. Graft collar 236, after trimmingexcess material, may be defined by lines 302 to 310 in FIG. 14.

FIGS. 15-18 show various embodiments of radiopaque (RO) markers placedupon stent portions which may be used for any suitable stent embodimentdiscussed herein. As shown, the various RO markers may be placed asclose to, straddling or proximal to, the top edge or proximal edge 402of the graft collar 236 in order to better orient the device for thephysician during implantation procedures. The RO markers 404 may beconstructed of a wound or clipped elongate element or strand of NiTi,Pt, composite NiTi/Pt—Ir or NiTi/Au, Au or any other known biocompatibleradiopaque materials. Markers 404 may be constructed in coilconfiguration made from coiled radiopaque wire or clip or any otherknown fashion. Markers 404 may be placed in an optional small transversesection of a dogbone structure 406 formed into the strut of a stent asshown in FIGS. 17 and 18 to maintain the position of the marker duringmanufacturing and loading into a delivery catheter. The dogbonestructure includes a pair of opposed enlarged portions or shoulderportions of the strut of the stent with a reduced section therebetween.The elongate element may be wound or clipped to the reduced section soas to be mechanically captured between the shoulder portions of thedogbone 406. Any of the stent, barb, radiopaque marker, graft bodysection, inflatable channel, inflatable sealing ring embodiments or thelike discussed herein may be included together in any suitable desiredcombination in an appropriate structure or configuration. In particular,any of the RO marker embodiments of FIGS. 15-18 may be used on any ofthe stent embodiments discussed herein. Any of the stent connectionmethods such as the use of flaps 306 as shown in FIGS. 7 and 14 may beused to connect any of the stent embodiments discussed herein to anysuitable stent graft body section.

Various embodiments of delivery systems are discussed herein that may beadapted for the deployment of the stent graft systems discussed herein.FIG. 19 shows a catheter delivery system 500 which includes a deliverycatheter 501 having a nosecone 502 which is placed initially into thepatient percutaneously or by any other known vascular surgicaltechnique. Nosecone 502 is at a proximal end of integral outer sheath503 which may house any of the stent graft system embodiments discussedherein as well as any other suitable stent graft embodiment. Other partsof system 500 include a flush port 506 and handle 508 for thephysician-operator to effect the deployment of the stent graft.

FIG. 22 shows an elevation view of a stent graft embodiment loaded ontodelivery catheter system 500 with the graft portion of the stent graftnot shown for clarity of illustration. Nosecone 502 is disposed at theproximal end of an elongate shaft 505 of the delivery catheter and issecured to a tubular member including a lumen (e.g. guide wire lumen503). The stent 230 is shown having distal portion 232 and proximalportion 234 (without the graft material shown) loaded on the catheterand placed in proximity over an optional basket 504 which is coaxiallydisposed within the stent 230. Basket 504 may be constructed out of aself-expanding or super elastic metal e.g. NiTi (Nitinol) or the like.The basket 504 may include a plurality of struts or tines 504 a.

Tines 504 a may be shape set in any manner that is desirable to aid inthe deployment of the stent graft. It will be appreciated that tines 504a may have one or more “humps” (e.g. camel hump feature, not shown) orthe tines may be constructed to have helical or otherwise twistedorientation to each other. In some embodiments, both the stent 230 andthe basket 504 may be loaded and secured via belts 506 and 508respectively. Belts 506 and 508 may be actuated or deployed by thephysician-operator via control means on the handle 508. The basket 504and the stent 230 may also be constrained and loaded in any othersuitable manner or fashion.

FIG. 23 depicts basket 504 after belt 508 has been released (or hasotherwise been released from constraint). Basket 504, as deployed,defines a substantially symmetric opened configuration having a largerouter transverse dimension or diameter than the basket 504 in aconstrained state as shown in FIG. 22. Not shown in FIG. 23 is thatbasket 504 is forcing the graft material of the stent graft in anopening biased position which is shown in FIG. 27. At this point, thephysician-operator may release the belt 506 (or any other knownrestraining means or devices for the stent); thus allowing the stent 230(if self-expanding) to expand and have the barbs (if any) engage theluminal surface of the patient's vessel 101.

Some embodiments of a delivery system for delivering a stent graft mayinclude the delivery catheter 501 with an elongate shaft having aproximal section and a distal section. The system may also include astent graft having a main graft body with an inner lumen configured forconfining a flow of blood therethrough. The stent graft may be loaded onthe proximal section of the delivery catheter 501 with the elongateshaft disposed within the inner lumen. In addition, the delivery systemmay also include the expandable centering device or basket 504 disposedon the elongate shaft within the inner lumen of the stent graft. Thecentering device 504 may be configured to expand from a radiallycontracted state as shown in FIG. 22 to a radially expanded state asshown in FIG. 23 for centering the elongate shaft and stent graft of thedelivery system toward a midline or longitudinal axis 702 of a patient'svessel 101 when introduced into the patient's vessel 101. In some cases,the centering device may include and expanding basket such as expandingbasket 504.

In some cases, the basket may include the elongate tines 504 a thatextend substantially parallel to the elongate shaft of the deliverycatheter in the radially contracted configuration as shown in FIG. 22.The elongate tines 504 a may also be configured to bow radiallyoutwardly from the elongate shaft in a substantially concentricarrangement in the radially expanded configuration as shown in FIG. 23.In some cases, the elongate tines are configured to self-expand to theradially expanded configuration and in some cases the elongate tines areconfigured to expand to the radially expanded configuration due to axialcompressive force applied to at least one end of the tines. For theself-expanding embodiments, the elongate tines may include aself-expanding or superelastic metal such as a NiTi alloy. Someembodiments of the centering device may have an outer transversedimension of about 50 mm to about 80 mm in the radially expanded stateand may be configured to expand to an outer transverse dimension that isat least as large as an inner transverse dimension of the inner lumen ofthe patient's vessel 101.

FIGS. 24-26 show a dynamic operation and deployment of basket 504 duringa deployment sequence of the stent graft. In some instances, thedelivery catheter 501 may be positioned within a patient's vessel 101such that the stent graft is axially positioned at a desired site withinthe patient's vessel 101 as shown in FIG. 27. The expandable centeringdevice may be in the radially contracted state during the positioningprocess in some cases. The expandable centering device may then beexpanded to the radially expanded state to center the elongate shaft andstent graft of the delivery system toward the longitudinal axis 702 ofthe patient's vessel 101. In addition, the stent 230 of the stent graftmay then be deployed so as to engage an inner luminal wall of thepatient's vessel. FIG. 24 shows the catheter 501 inserted into a vessel101 of a patient having a TAA condition 202. As shown, the deliverycatheter 501 would tend to lie along the greater-curve 208 of the aortabecause of the mechanical stiffness of the catheter. It will beappreciated, however, that due to variations in patient anatomy andgeometry that the delivery catheter 501 might also tend to lie along thelesser-curve, instead of the greater-curve. In some cases however, itmay be desirable to have the catheter move and lie more along themidline or longitudinal axis 702 of the aorta prior to device deploymentof the stent graft from the delivery catheter 501.

Nosecone 502 is shown also along greater-curve 208. Midline 702 showsthe middle of the thoracic region of the aorta 101 itself. If the stentgraft were to be deployed with the catheter as shown in FIG. 24, thereis a possibility that the stent and the graft portions of the stentgraft may not deploy in a desirable manner. For example, the stentportion might miss the desired landing zone and there may be someundesirable positioning of graft material due to an asymmetricdeployment which might compromise the integrity of the later-filledsealing rings in producing an sufficient seal and exclusion of theaneurysm 202 from blood flow.

FIG. 26 shows how an expandable basket 504 may alleviate some of theseundesirable conditions. Basket 504, as deployed, may help to center thestent graft along midline 702 prior to deployment of the stent portionand subsequent filling of inflation rings in the graft material. In someinstances, deploying the stent may include deploying a stent disposed ata proximal end of the stent graft disposed towards a source of bloodflow in the patient's vessel 101. In some embodiments wherein theexpandable centering device includes a basket 504, expanding theexpandable centering device may include allowing self-expanding elongatetines 504 a of the basket 504 to self-expand to the radially expandedstate. In some embodiments expanding the expandable centering deviceincludes axially compressing at least one end of elongate tines 504 a ofthe basket 504 to shorten a separation of the proximal ends and distalends of the elongate tines 504 a of the basket 504 and expand a centerportion of the tines 504 a to the radially expanded state. In somecases, expanding the expandable centering device to the radiallyexpanded state to center the elongate shaft and stent graft of thedelivery system toward the longitudinal axis of the patient's vessel 101may include expanding the expandable centering device, such as basket504, or balloon 710 discussed below, to an outer transverse dimensionwhich is about the same as a transverse dimension of an inner lumen ofthe patient's vessel 101 at a position of the expandable centeringdevice.

Some centering device embodiments may also include an inflatablestructure such as the inflatable structure 710 shown in FIG. 28. Theinflatable structure 710 may have a collapsed deflated state (not shown)and an enlarged inflated state as shown in FIG. 28. In some cases, inthe enlarged inflated state, the centering device 710 may have asubstantially cylindrical configuration including vias that extend fromports 714 in a proximal surface of the centering device 710 torespective ports in a distal surface of the centering device. The vias714 may be configured to provide for continuous flow of blood throughthe inflatable centering device and delivery system during inflation ofthe centering device and deployment of the stent graft. In some cases,the expandable vias have a cumulative cross section that is at leastabout 5 percent to about 10 percent of the total cross section of thecentering device in an expanded state. In some instances, the expandablecentering device may include a configuration that is radially concentricwith the elongate shaft in the enlarged inflated state.

FIG. 28 shows an embodiment of an inflatable balloon 710 which may beused in place of or in addition to basket 504 and which serves to aidthe catheter to tend toward midline 702 of the patient's vessel 101prior to deployment. Balloon 710 includes a plurality of films or layersof flexible material that may be hermetically sealed together orotherwise joined to form a fluid tight interior volume that onceinflated may assume an annular or circular shape. The balloon 710 mayalso include a structure or structures that allow blood to flowtherethrough. For some embodiments, via holes or vias 714 may pass froma proximal end of the balloon 710 to a distal end of the balloon 710 ata radial position disposed inwardly of the outer radial surface of theballoon 710. The vias 714 may extend from a port on a proximal surfaceof the balloon 710 to a respective port on a distal surface of theballoon 710. Balloon 710 may be mated to an elongated tubular member 712by any suitable method or means, in particular, via adhesives or thelike. The elongated tubular member 712 may have an inner lumen 713 thatmay be used to accommodate a guidewire or the like as shown in FIG. 29.

Ports (not shown on elongated tubular member 712) in fluid communicationwith an interior volume of the balloon 710 and with an inflation lumen715 may be used to inflate balloon 710 with air, gas or liquid or thelike. The inflation of balloon 710 may be carried out by injection of aninflation fluid from a source of pressurized fluid 716, through supplylumen 717, through inflation lumen 715 and into the interior volume ofthe balloon 710. FIG. 30 is an end view of balloon 710 once inflatedillustrating the vias. There may be other devices to effect thecentering of the delivery catheter 501 prior to deployment andembodiments of the present invention encompass all such known means anddevices. It may be merely desirable that the delivery catheter 501 beinduced to lie more along the midline or longitudinal axis 702 of theaorta prior to device deployment. In some cases, expanding theexpandable centering device may include inflating an interior volume ofthe inflatable structure with a biocompatible fluid to expand theinflatable structure to the radially expanded state. For someembodiments, the interior volume of the inflatable structure may beinflated through an inflation lumen with a fluid from a source ofpressurized fluid. The source of pressurized fluid may include a syringefor some embodiments and inflating the interior volume of the inflatablestructure may include injecting fluid from an interior volume of thesyringe through the inflation lumen and into the interior volume of theinflatable structure. Any suitable inflation fluid may be used forinflating the interior volume of the inflatable structure includingbiocompatible fluids such as saline solution.

FIGS. 31 and 32 illustrate an embodiment of a deployment structure 800for the stent 230 or any other suitable stent of a stent graft discussedherein which may be incorporated into a delivery system having adelivery catheter such as delivery catheter 501. The main graft body ofthe stent graft loaded onto the delivery catheter is not shown in FIG.32 for purposes of clarity of illustration. The delivery catheter 501shown in FIG. 32 may include many of the same features, dimensions andmaterials as those of the delivery catheter embodiments 501 discussedherein. As shown in FIGS. 31 and 32, sleeve 802 is slidably disposedover the elongate shaft of the delivery catheter 501 and may beconfigured to surround and constrain barbs 235 once the stent 230 isloaded into delivery catheter 501 and the sleeve is disposed in a distalposition covering the barbs 235 of the stent 230. The physician-operatormay deploy basket 504 as described herein by shortening the separationof the proximal ends 509 of the tines of the expandable basket relativeto the distal ends 511 of the tines of the elongate basket 504.Thereafter, an axial force, in a proximal direction as indicated byarrow 815, may be applied to push rod 804 which may be slidably disposedwithin or adjacent an elongate multi-lumen structure or shaft 806. Oncesleeve 802 is pushed proximally beyond mechanical mating with or radialconstraint of barbs 235, the stent portion would deploy in an outwardradial direction.

FIGS. 33 and 34 show yet another embodiment of the delivery system 500which is configured to deploy stent graft embodiments discussed herein.FIGS. 33 and 34 do not show the main graft body of the stent graft forpurposes of clarity of illustration. FIG. 33 shows the stent graft asloaded onto the delivery catheter 501 in a radially constrained statesuitable for percutaneous delivery through the vessels 101 of apatient's body. In this embodiment, there are shown multiplebelt/constraints for both stent 902 and basket 504—with belts 506 a and506 b being disposed about and radially constraining self-expandingstent 902 and belts 508 a and 508 b disposed about and radiallyconstraining basket 504. FIG. 34 shows the belts 508 a and 508 breleased from constraint of the basket 504 which is shown in a radiallyexpanded state with a shorter axial separation between proximal anddistal ends 509 and 511 relative to the axial separation shown in FIG.33. The belts 508 a and 508 b may be held or locked into a constrainingconfiguration by a trigger wire (not shown) and deployed by retractionof the trigger wire as shown in FIG. 36 and discussed below. In somecases, a physician-operator may deploy basket 504 in stages via belts508 a and 508 b for a more accurate and controlled deployment.

In some cases, an operator may also wish to deploy stent 902 in stagesfor a more accurate placement or better control of the stent deployment.In particular, FIG. 34 shows the partial deployment of stent 902 whereina first belt 508 a and a second or final constraint or belt 508 b hasbeen released from a constraining configuration with the retraction of atrigger wire or any other suitable means. However, a stent crownconstraint 915 which may have features and/or mode of operation similarto those of constraint 1000 shown in FIG. 35 and discussed below, hasyet to be actuated or released—which may allow for repositioning of thestent graft by the physician under fluoroscopy. Thereafter, an operatormay deploy constraint 915 to completely deploy stent 902. The belts 508a, 508 b, 506 a and 506 b may also be deployed or released in anydesired order or sequence in order to achieve a desired partiallydeployed state of either the basket 504 or the stent 902.

FIGS. 35-37 depict an embodiment of loading a stent of a stent graftonto a delivery catheter of a delivery system. Constraint system 1000comprises a crown constraint sleeve 1002 and strut support assembly1004. In FIG. 35, both crown constraint 1002 and stent support assembly1004 are shown as they would be configured in a docket position,constraining a stent (without the stent shown for purposes ofillustration). FIG. 36 shows the same configuration but with stent 1006loaded and constrained by constraint system 1000. FIG. 37 shows theconfiguration of constraint system 1000 upon removing the constraintimposed by the constraint system 1000 on the stent 1006 and deployingthe stent in a vessel lumen 101 of the patient. It may be seen thatstrut support assembly 1004 has moved distally with respect to crownconstraint sleeve 1002 via a pull wire 1003, push rod, spring action orany other known manner of effecting slidable coupling. After deployment,it is desirable that crown constraint 1002 and strut support assembly1004 reconnect, so as to not capture or engage with the tissue of apatient's vessel 101. Belts are also shown released and extendingradially from delivery catheter.

Some embodiments of a delivery system for delivering a stent graftinclude the delivery catheter 501 having an elongate shaft with aproximal section and a distal section. The delivery catheter 501 mayalso include the releasable stent constraint system 1000 disposed on theproximal section elongate shaft. In some cases, the stent constraintsystem 1000 may include the crown constraint sleeve 1002 having a rigidtubular structure disposed about the elongate shaft with a plurality ofcrown restraint extensions extending distally from the crown constraintsleeve 1002. The crown restraint extensions may generally becircumferentially spaced from each other. The catheter 501 may alsoinclude the strut support assembly 1004 which is slidingly disposedabout the elongate shaft distally adjacent the crown constraint sleeve1002. The strut support assembly 1004 may include a plurality of thestrut supports which are circumferentially aligned with respective crownrestraint extensions of the crown constraint sleeve 1002 and whichextend radially away from a longitudinal axis 1005 of the elongate shaft1007.

The constraint system has a docked state wherein the strut supports formclosed but openable crown constraint passages 1009 between the strutsupports and respective crown constraint extensions of the crownconstraint sleeve 1002. The constraint system also includes an openstate wherein the strut support assembly 1004 is spaced axially awayfrom the crown constraint sleeve 1002 and the crown restraint passagesare opened to allow radial expansion of stent crowns disposed therein.The delivery system may also include a stent graft including aself-expanding stent 230 secured to a proximal end of a main graft body.In some cases, the main graft body may have an inner lumen configuredfor confining a flow of blood therethrough. The stent graft is loaded onthe proximal section of the delivery catheter 501 with the elongateshaft 1007 disposed within the inner lumen and a plurality of proximalstent crowns disposed within closed crown restraint passages 1009 of thestent constraint system 1000. So configured, the strut support assembly1004 is in a docket state.

In some cases, the crown constraint sleeve 1002 may be secured to theelongate shaft 1007 and the strut support assembly 1004 may be slidinglydisposed about the elongate shaft 1007 distally adjacent the crownconstraint sleeve 1002. In addition, such a strut support assembly 1004may be resiliently biased towards the crown constraint sleeve 1002 in anaxial direction. In some instances, the strut support assembly 1004 maybe resiliently biased towards the crown constraint sleeve 1002 in anaxial direction by an axially oriented spring 1011 disposed between thestrut support assembly 1004 and the elongate shaft 1007. For some otherembodiments, the strut support assembly 1004 may be secured to theelongate shaft 1007 and the crown constraint sleeve 1002 may beslidingly disposed about the elongate shaft 1007 proximally adjacent thecrown constraint sleeve 1002. In some cases, the delivery system mayalso include at least one releasable belt 1013 disposed about the stent1006 of the stent graft. The at least one releasable belt 1013 may belocked in a constrained configuration about the stent 1006 with aremovable trigger wire 1015 that may be axially retracted in order torelease the constrained belts which are mechanically captured in aconstraining configuration by the trigger wire 1015.

In use, a stent graft loaded on a delivery catheter having such aconstraint system 1000 may be axially positioning at a desired sitewithin the patient's vessel 101 as shown in FIG. 27. Thereafter, thecrown restraint sleeve 1002 may be axially separated from the strutsupport assembly 1004 so as to open the crown restraint passages 1009allowing crowns of the stent 1006 contained within the crown restraintpassages 1009 to radially expand. In some instances, the crownconstraint sleeve 1002 may be secured to elongate shaft 1007 and thestrut support member 1004 may be slidingly disposed about elongate shaft1007 distally adjacent the crown constraint sleeve 1002. In such a case,axially separating the crown restraint sleeve 1002 from the strutsupport assembly 1004 so as to open the crown restraint passages 1009allowing crowns of the stent 1006 contained within the crown restraintpassages 1009 to radially expand may include displacing the strutsupport member 1004 in an axial direction relative to the crownconstraint sleeve 1002 and the elongate shaft 1007. In some cases, thestrut support assembly 1004 may be secured to the elongate shaft 1007and the crown constraint sleeve 1002 is slidingly disposed aboutelongate shaft 1007 proximally adjacent the crown constraint sleeve1002. In such an embodiment, axially separating the crown restraintsleeve 1002 from the strut support assembly 1004 so as to open the crownrestraint passages 1009 allowing crowns of the stent 1006 containedwithin the crown restraint passages 1009 may include displacing thecrown constraint sleeve 1002 in a proximal direction relative to thestrut support assembly 1004 and the elongate shaft 1007.

In some cases, the crown constraint sleeve 1002 may be secured to theelongate shaft 1007 and the strut support member 1004 may be slidinglydisposed about elongate shaft 1007 distally adjacent the crownconstraint sleeve 1002. In such a case, axially separating the crownrestraint sleeve 1002 from the strut support assembly 1004 so as to openthe crown restraint passages 1009 allowing crowns of the stent 1006contained within the crown restraint passages 1009 to radially expandmay include displacing the strut support member 1004 in an axialdirection relative to the crown constraint sleeve 1002 and the elongateshaft 1007. For such embodiments, the strut support assembly 1004 may beresiliently biased towards the crown constraint sleeve 1002 in an axialdirection and displacing the strut support assembly 1004 in an axialdirection relative to the crown constraint sleeve 1002 and the elongateshaft 1007 may include retracting the strut support assembly 1004 byapplying axial displacement in a distal direction on a pull rod or pullwire 1003 that is secured to the strut support assembly 1004 and extendsdistally to a distal end of the elongate shaft 1007.

In some cases (not shown), the strut support assembly 1004 may besecured to the elongate shaft 1007 and the crown constraint sleeve 1002may be slidingly disposed about elongate shaft 1007 proximally adjacentthe crown constraint sleeve 1002. For such an embodiment, axiallyseparating the crown restraint sleeve 1002 from the strut supportassembly 1004 so as to open the crown restraint passages 1009 allowingcrowns of the stent 1006 contained within the crown restraint passages1009 may include displacing the crown constraint sleeve 1002 in aproximal direction relative to the strut support assembly 1004 and theelongate shaft 1007. In such a case, the crown constraint sleeve 1002may be resiliently biased towards the strut support assembly 1004 in anaxial direction and displacing the crown constraint sleeve 1002 in anaxial direction relative to the strut support member 1004 and theelongate shaft 1007 may include displacing the crown constraint sleeve1002 by applying axial displacement in a proximal direction on a pushrod (not shown) that is secured to the crown constraint sleeve 1002 andextends distally to a distal end of the elongate shaft 1007.

FIG. 38 illustrates an embodiment of loading the constraint system 1000shown in FIGS. 35-37 which may be incorporated into any suitabledelivery system discussed herein. In this embodiment, strut support 1004is held rigidly with respect to the delivery catheter 501 and crownconstraint sleeve 1002 is slidably attached to the delivery catheter 501and, upon removing of the constraint of the stent, crown constraintsleeve 1002 is moved proximally with respect to the catheter.Additionally, stent 1006 is shown flared out in the distal portion dueto release of a first belt constraint 1007. The slidable movement ofcrown constraint sleeve 1002 may be accomplished afterphysician-operator has an opportunity to reposition the deliverycatheter 501 within the vessel 101 of the patient with the aid ofvisualization such as by fluoroscopy.

FIG. 39 shows an embodiment of a constraint system 1100 for loading anysuitable stent discussed herein and which may be incorporated into anysuitable delivery system discussed herein. FIG. 39 shows a constraintconfiguration after release and deployment of the stent. Crownconstraint assembly 1002 b has been moved slidably in a distal directionas shown by arrow 1125 relative to support structure 1004 b. Returnspring 1008 is used to dock crown constraint assembly 1002 b to support1004 b to radially constrain the proximal stent crowns of the stentgraft. The crown constraint assembly may be axially displaced as shownby a pull wire 1003 as shown in FIG. 35 and discussed above. The crownconstraint assembly 1002 b includes proximally extending crown elementswhich are circumferentially spaced from each other and configured toform openable constraint apertures similar to apertures 1009 shown inFIG. 35 when the assembly 1002 b is axially engaged with supportstructure 1004 b.

FIGS. 40-44 show an embodiment of a constraint system for loading astent of a stent graft, including any suitable stent or stent graftembodiments discussed herein. The constraint system may also beincorporated into any suitable delivery system discussed herein.Nosecone 1102 is the proximal most portion of the delivery catheter andis mated to sleeve 1104. Sleeve 1104 provides the constraint for thestent and the barbs, together with support 1106 and crown constraintassembly 1108. Spring 1110 provides a mechanism for the mating/de-matingof crown constraint assembly 1108 and support 1106. FIG. 40 shows theconfiguration of the constraint system immediately after the stent hasbeen fully deployed into the patient.

FIG. 41 shows the constraint in a configuration such as would be thecase with the stent loaded (stent not shown) and prior to release of anyconstraint. It should be noted that support 1106 has cantileveredportions 1106 a that may be spring loaded so that when support 1106 isinside sleeve 1104 the cantilevered portions are compressed to a smallerdimension and when support 1106 is moved distally from sleeve 1104 (asshown in FIG. 35), then the cantilevered portions expand as shown by thedashed lines of 1106 a in FIG. 35; thus not allowing the support 1106 toreturn inside sleeve 1104.

FIGS. 42 through 44 show a sequence of figures whereby the stent isreleased from a constrained configuration. FIG. 42 shows theconfiguration where the stent is fully loaded prior to deployment. FIG.43 shows the configuration where the support 1106 and crown 1108 havebeen moved relative with respect to sleeve 1104. In this configuration,stent (not shown) has its distal portion flared outward; but the apicesof the stent and barbs are still constrained by crown 1108 and support1106 which are axially pushed together to confine the proximal crowns ofthe stent. FIG. 44 shows the configuration immediately after fulldeployment of the stent wherein the crown 1108 has been moved distallyrelative with respect to support 1106 to open a gap between the support1106 and the crown constraint assembly 1108 to allow the stent toself-expand.

FIGS. 45-47 show an embodiment of a constraint system 1200 for use on adelivery catheter of a delivery system wherein a stent may be partiallydeployed and have barbs which are disposed on the stent mechanicallypushed radially outward to aid the engagement of the barbs with thepatient's vessel. FIG. 45 shows sleeve 1202 locked in a first positionwith lock 1208 (which in this case is constructed on one of the tines ofan expandable basket 1207). Lock 1208 is shown poking through a firsthole 1209 in sleeve 1202 and will be allowed to move to a second hole1210 disposed on a different axial position of sleeve 1202. Stent 1206and barbs 1206 a are shown to be fully constrained by a crown section1203 of sleeve 1202 disposed adjacent to support 1204.

FIG. 46 depicts a configuration when lock 1208 has been axiallydisplaced to the second hole position 1210. In this configuration, stent1206 has its distal portion in a flared position while the barbs 1206 aare still constrained by crowns of crown section 1203. Tines 1210 of thebasket 1207 are shown as deployed.

FIG. 47 shows a configuration with barbs 1206 a released from allconstraint and tines 1210 of the basket 1207 as deployed. It may bedesirable to have first housing section 1220 to be slidably connected tosleeve 1202 so that moving sleeve 1202 towards housing section 1220 mayfurther expand tines 1210 of the basket. By doing so, tines 1210 maypush against stent struts or the graft material (not shown) with greaterradial force. This may allow some of all of barbs 1206 a to betterengage the luminal surface of the patient's vessel 101.

Some embodiments of a delivery system for delivering a stent graft mayinclude a delivery catheter 501 having an elongate shaft 1212 with aproximal section and a distal section. The delivery catheter 501 mayalso include the releasable stent constraint system 1200 disposed on theproximal section of elongate shaft 1212 as shown in FIG. 45. The stentconstraint system 1200 may include the stent constraint sleeve 1202which may have a rigid tubular structure slidably disposed about theelongate shaft 1212. The stent constraint sleeve 1202 may be axiallytranslatable between a distal position as shown in FIG. 45 and aproximal position as shown in FIG. 46. The stent constraint sleeve 1202may also include a plurality of the crown sections 1203 that extenddistally from the crown constraint sleeve 1202 and are circumferentiallyspaced from each other. The constraint system 1200 may further includethe plurality of strut supports 1204 which are secured to the elongateshaft 1212 distally adjacent the stent constraint sleeve 1202. The strutsupports 1204 may be circumferentially spaced from each other and extendradially outward or away from a longitudinal axis 1209 of the elongateshaft 1212.

Such a constraint system 1200 may have a constraint state wherein thestent constraint sleeve 1202 is disposed in the distal position as shownin FIG. 45 and a deployment state wherein the stent constraint sleeve1202 is in the proximal position as shown in FIG. 46. The deliverycatheter 501 may also include the expandable basket 1207 having aplurality of elongate tines 1210 which are disposed in a substantiallytubular configuration, which extend axially along the elongate shaft1212 of the delivery catheter 501 in a position distally adjacent thestent constraint sleeve 1202, and which are configured to bow radiallyoutward upon reduction of a separation between proximal ends 1215 of theelongate tines 1210 and distal ends 1217 of the elongate tines 1210. Inaddition, the delivery system 501 may have a stent graft 1218 includinga flexible main graft body 1221 and a self-expanding stent, such asself-expanding stent 1206. The main graft body portion 1221 may includean inner lumen 1222 configured for confining a flow of bloodtherethrough, a proximal end 1223 and a distal end. The self-expandingstent 1206 may have a proximal end, a distal end secured to the proximalend of the main graft body 1221, and a plurality of proximal stentcrowns 1223 which include at least one barb 1206 a.

For such a configuration, the stent graft 1218 may be loaded on theproximal section of the elongate shaft 1212 with the elongate shaftdisposed within the inner lumen of the graft body 1222. The plurality ofproximal stent crowns 1223 which include at least one barb 1206 a may bedisposed within and radially constrained by the stent constraint sleeve1202 with the stent constraint sleeve 1202 in the distal position. Inaddition, at least one elongate tine 1210 of the expandable basket 1207may be disposed beneath a stent crown 1223 that includes a barb 1206 a,the at least one elongate tine 1210 being configured to apply outwardradial force on the stent crown 1223 upon deployment of the stent 1206and expansion of the expandable basket 1207.

The entirety of each patent, patent application, publication anddocument referenced herein hereby is incorporated by reference. Citationof the above patents, patent applications, publications and documents isnot an admission that any of the foregoing is pertinent prior art, nordoes it constitute any admission as to the contents or date of thesepublications or documents.

Modifications may be made to the foregoing without departing from thebasic aspects of the invention. Although embodiments of the inventionhave been described in substantial detail with reference to one or morespecific embodiments, those of ordinary skill in the art will recognizethat changes may be made to the embodiments specifically disclosed inthis application, yet these modifications and improvements are withinthe scope and spirit of the invention.

Embodiments illustratively described herein suitably may be practiced inthe absence of any element(s) not specifically disclosed herein. Thus,for example, in each instance herein any of the terms “comprising,”“consisting essentially of,” and “consisting of” may be replaced witheither of the other two terms. The terms and expressions which have beenemployed are used as terms of description and not of limitation and useof such terms and expressions do not exclude any equivalents of thefeatures shown and described or portions thereof and variousmodifications are possible within the scope of the invention claimed.The term “a” or “an” can refer to one of or a plurality of the elementsit modifies (e.g., “a reagent” can mean one or more reagents) unless itis contextually clear either one of the elements or more than one of theelements is described. Thus, it should be understood that althoughembodiments have been specifically disclosed by representativeembodiments and optional features, modification and variation of theconcepts herein disclosed may be resorted to by those skilled in theart, and such modifications and variations are considered within thescope of this invention.

Certain embodiments of the invention are set forth in the claim(s) thatfollow(s).

What is claimed is:
 1. A delivery system for delivering a stent graft, the delivery system comprising: a delivery catheter comprising an elongate shaft with a proximal section and a distal section; a stent graft having a main graft body with an inner lumen configured for confining a flow of blood therethrough and a stent portion secured to an end portion of the main graft body and extending externally to the main graft body, the stent graft being loaded on the proximal section of the delivery catheter with the elongate shaft disposed within the inner lumen; and an expandable centering device having a central portion disposed on the elongate shaft within the inner lumen of the main graft body and external to the stent portion, the central portion configured to fully radially expand within the inner lumen of the main graft body while the stent portion is radially constrained to radially expand the main graft body such that the elongate shaft and stent graft are centered toward a midline longitudinal axis of a patient's vessel while the stent portion is in a radially constrained state; and further comprising a constraining device configured to radially constraint the stent portion in the radially constrained state while the main graft body is radially expanded.
 2. The delivery system of claim 1 wherein said centering device comprises an expanding basket, the basket including elongate tines that extend substantially parallel to a portion of the elongate shaft of the delivery catheter in the radially contracted configuration and are configured to bow radially outwardly from said portion of the elongate shaft in a substantially concentric arrangement in the radially expanded configuration.
 3. The delivery system of claim 2 wherein the elongate tines are configured to self-expand to the radially expanded configuration.
 4. The delivery system of claim 3 wherein the elongate tines comprise of a self-expanding metal.
 5. The delivery system of claim 4 wherein the self-expanding metal comprises NiTi alloy.
 6. The delivery system of claim 3 wherein the elongate tines comprise of a superelastic metal.
 7. The delivery system of claim 6 wherein the superelastic metal comprises NiTi alloy.
 8. The delivery system of claim 2 wherein the elongate tines are configured to expand to the radially expanded configuration due to axial compressive force applied to at least one end of the tines.
 9. The delivery system of claim 1 wherein the centering device has an outer transverse dimension of about 50 mm to about 80 mm in the radially expanded state.
 10. The delivery system of claim 1 wherein the centering device is configured to expand to an outer transverse dimension that is at least as large as an inner transverse dimension of the inner lumen of the patient's vessel.
 11. The delivery system of claim 1, wherein the centering device comprises an expanding basket, the basket including elongate tines that extend substantially parallel to the longitudinal axis of the portion of the elongate shaft disposed under said tines when said elongate tines are in a contracted configuration.
 12. The delivery system of claim 1, wherein the centering device comprises an expanding basket, the basket including elongate tines having a central portion substantially parallel to the longitudinal axis of the portion of the elongate shaft disposed under said tines when said elongate tines are in an expanded configuration.
 13. The delivery system of claim 1, wherein the stent portion comprises a proximal stent portion connected or integral with a distal stent portion.
 14. The delivery system of claim 13, wherein the distal stent portion is at least partially secured to the main graft body.
 15. The delivery system of claim 14, wherein the stent portion includes at least one barb extending radially outward therefrom.
 16. A method of centering a delivery system during deployment of a stent graft, comprising: a. providing a delivery system for delivering a stent graft, the delivery system comprising: a delivery catheter comprising an elongate shaft with a proximal section and a distal section, a stent graft having a main graft body with an inner lumen configured for confining a flow of blood therethrough and a stent portion secured to an end portion of the main graft body and extending externally to the main graft body, the stent graft being loaded on the proximal section of the delivery catheter with the elongate shaft disposed within the inner lumen, and an expandable centering device having a central portion disposed on the elongate shaft within the inner lumen of the main graft body and external to the stent portion, the central portion configured to radially expand within the inner lumen of the main graft body while the stent portion is radially constrained to radially expand the main graft body such that the elongate shaft and stent graft are centered toward a midline longitudinal axis of a patient's vessel while the stent portion is in a radially constrained state; b. positioning the delivery catheter within a patient's vessel such that the stent graft is axially positioned at a desired site within the patient's vessel with the expandable centering device in a radially contracted state; c. expanding the expandable centering device to a radially expanded state, within the inner lumen of the main graft body and externally of the stent portion, to center the elongate shaft and stent graft of the delivery system toward the longitudinal axis of the patient's vessel; and d. deploying the stent of the stent graft so as to engage an inner luminal wall of the patient's vessel, after expanding the expandable centering device.
 17. The method of claim 16 wherein deploying the stent comprises deploying a stent disposed at a proximal end of the stent graft disposed towards a source of blood flow in the patient's vessel.
 18. The method of claim 16 wherein the expandable centering device comprises a basket and wherein expanding the expandable centering device comprises allowing self-expanding elongate tines of the basket to self-expand to the radially expanded state.
 19. The method of claim 16 wherein the expandable centering device comprises a basket and wherein expanding the expandable centering device comprises axially compressing at least one end of elongate tines of the basket to shorten a separation of the proximal ends and distal ends of the elongate tines of the basket and expand a center portion of the tines to the radially expanded state.
 20. The method of claim 16 wherein the expandable centering device comprises an inflatable structure and wherein expanding the expandable centering device comprises inflating an interior volume of the inflatable structure with a biocompatible fluid to expand the inflatable structure to the radially expanded state.
 21. The method of claim 20 wherein the interior volume of the inflatable structure is inflated through an inflation lumen with a fluid from a source of pressurized fluid.
 22. The method of claim 21 wherein the source of pressurized fluid comprises a syringe and inflating the interior volume of the inflatable structure comprises injecting fluid from an interior volume of the syringe through the inflation lumen and into the interior volume of the inflatable structure.
 23. The method of claim 20 wherein the biocompatible fluid comprises saline solution and inflating an interior volume of the inflatable structure comprises inflating the interior volume with saline solution.
 24. The method of claim 16 wherein expanding the expandable centering device to the radially expanded state to center the elongate shaft and stent graft of the delivery system toward the longitudinal axis of the patient's vessel comprises expanding the expandable centering device to an outer transverse dimension which is about the same as a transverse dimension of an inner lumen of the patient's vessel at a position of the expandable centering device.
 25. A delivery system for delivering a stent graft, the delivery system comprising: a delivery catheter comprising an elongate shaft with a proximal section and a distal section; a stent graft having a main graft body with an inner lumen configured for confining a flow of blood therethrough and a stent portion secured to an end portion of the main graft body and extending externally to the main graft body, the stent graft being loaded on the proximal section of the delivery catheter with the elongate shaft disposed within the inner lumen; and an expandable centering device having a central portion disposed on the elongate shaft within the inner lumen of the main graft body and external to the stent portion, the central portion configured to radially expand within the inner lumen of the main graft body while the stent portion is radially constrained to radially expand the main graft body such that the elongate shaft and stent graft are centered toward a midline longitudinal axis of a patient's vessel while the stent portion is in a radially constrained state, wherein said centering device comprises an inflatable structure including: a collapsed deflated state, and an enlarged inflated state with a substantially cylindrical configuration including vias that extend from ports in a proximal surface of the centering device to respective ports in a distal surface of the centering device for continuous flow of blood through the centering device and delivery system during inflation of the centering device and deployment of the stent graft; and further comprising a constraining device configured to radially constrain the stent portion in the radially constrained state while the main graft body is radially expanded.
 26. The delivery system of claim 25, wherein the expandable vias have a cumulative cross section that is at least about 5 percent to about 10 percent of the total cross section of the centering device in an expanded state.
 27. The delivery system of claim 25, wherein the expandable centering device comprises a configuration that is radially concentric with the elongate shaft in the enlarged inflated state. 